Hey @Tremzoff ,
I think it is not that trivial to use the Camunda-bpm-mail example with Camunda Run. At the moment, connectors are not supported in Camunda run. The project uses the connector mechanism. You can add the jar files to Camunda run to be able to use connectors likes discussed here. Then you could try to add the mail project to run as well. But I am not 100% if it will work. The Camunda-bpm-mail was originally not built for Camunda run.
An easier way might be to use this external task worker to send out emails from Camunda Run.
I hope this helps
Cheers
Nele